In Japanese Patent Laid-Open No. Hei 2-70919, an exhaust control device is disclosed in which a rotary valve is disposed in the middle of exhaust pipes individually communicating with a plurality of respective exhaust ports provided in a cylinder head and is shared by the exhaust pipes.
In the exhaust control device disclosed in Japanese Patent Laid-Open No. Hei 2-70919, a valve housing different from the exhaust pipes is attached to the exhaust pipes. Therefore, it cannot be avoided to increase the number of component parts. In addition, when replaced, the exhaust pipe is needed to be replaced along with the rotary valve.